What Causes Dry Heaves While Treating Severe Constipation?

, I have been constipated for 7 days. I went in for my physical and share with my doctor and she told me to take Latulose I took more than the prescribed amount but nothing happened. I went to Urgent Care they did x-rays to make sure that was not a blockage but there was not. And they had me take Maalox period two days later I called my doctor and she told me to go under emergency. I went to emergency. They did blood work to make sure there was not any infection and everything was fine. They gave me Fleet liquid to take sent me home.. I drank half a bottle that night. And the other half the next morning. Which was a total of 10 ounces. It has been 24 hours and I have a l eliminated just a little bit of stool. I ve been drinking a lot of fluids about a gallon a day. Today I have drink about 60 ounces. About an hour ago I started throwing up mainly the Fleet enema and water but not a lot of liquids. I ve done that twice now. But now I am having dry heaves. Is there anything I can take at this point or should do because of the dry heaves